In Homefront/Paradise Lost, Odo could instnatly tell that Admiral Leyton was a changeling. Here he takes a whole episode to work out that Martok is also a changeling.

Just how powerful are disrupters compared to phasers, anyway? In the mirror universe, mirror-Odo exploded when he was hit by a single phaser beam. But it takes a good dozen or more disrupter blasts to kill this changeling.

Great Moment :

I'm going to break with tradition and name an episode title as the best thing about it. It's not that there are no good bits in the episode, but "Apocalypse Rising" is just such a cool-sounding title!

Plotline

With hostilities raging between the Federation and the Klingon Empire, Sisko must penetrate the Klingon fortress of Ty'Gokor in a desperate bid to prove that Gowron himself has been replaced by a Changeling.